Actually, it's more like...
Coming to a laboratory near you.
Yep, they're moths... They're giant... They're
robots... And... They're REAL! Scientists hope to use them for secret
surveillance in enemy territory! Pretty cool, huh?
Built by a research scientist named Charles Ellington,
this "thing" is called Flapper. It's got a wing span of 40
inches (that's more than a yard and about a meter) and they are using it
to study how insects fly.
Scientists used to think that insect wings worked the
same way an airplanes wings work...
Airplane wings are more curved on the top than on the
bottom. As a wing slices through air, the air above has further to go to
reach the back of the wing (because of the big curve) and moves faster
than the air below the wings.
Air that moves quickly has less pressure than air that
moves slowly. That means there is less pressure on the top of the wing
than below it. Less pressure on top means that the wing moves up! Check it
out:
But they found out that insect wings don't work like this at all!
How'd they figure this out? They stuck one of the little buggers
in a wind tunnel (this is where they blow
a bunch of wind with big fans at something and watch what happens)
and shot smoke at it while it flew. It turns out that insects don't have
enough of this airplane wing kind of lift to fly, so they kept
investigating...
But, there was one problem: Bugs wings flap way too fast to see
what's going on! They're really really small too!
So Charles built Flapper. It took 9 months and cost about $60,000. Like we
said, it's giant and he can control the speed of the flapping to better
see what's going on. Flapper takes about 3 seconds to do one wing beat.
Ok, back to the experiment... Flapper starts flapping while they
have a bunch of smoke around him. (The smoke is so they can see the air
swirling around!) Do you know what happened? Little tornados of smoke formed
on the surface of Flapper's wings - one on the left and one on the right! These
little tornados are called vortices. They now think that is how insects
fly... They are still investigating though.
